ubports.chat ssl certificate expired

I have been having trouble with Riot not connecting to the ubports.chat matrix server on my laptop (fluffychat is not having any issues). While trying to figure out what was wrong I noticed that the ssl certificate for ubports.chat expired on August 21st. I don't know who manages that, but since ubports is in the domain, I figured this was a good place.
I was able to encounter this error here: https://ubports.chat:8448
Here is what I see in firefox:

EDIT: Accepting the expired cert did fix Riot (Riot.im in firefox) for me. Though it isn't a good solution.